1. Field of the Invention
This invention relates to an improved cage lock for securing a laboratory animal cage in a cage and rack system and, in particular, to a cage lock which releasably secures cages within a cage and rack system.
2. Description of Related Art
Cage and rack systems used to store laboratory animals are well known in the art. Typically, such systems include a plurality of shelves, each shelf containing a plurality of cages which provide air and/or water to the animals stored therein. The cages are generally removable from the rack to provide access to the laboratory animals for feeding and testing, and to provide access to the cages for cleaning, maintenance and transport. To accommodate these requirements, rack systems are typically designed so that the cages can slide in and out of the rack system. When a laboratory animal is housed and maintained in the cage, the cage may be secured in place in the rack with a cage lock to prevent the cage from inadvertently sliding out from the rack. One concern of not securing a cage in the rack is that a sliding cage can cause suffocation of the laboratory animal within the cage by a disruption in air supply, dehydration of the laboratory animal by a disruption of water to the cage drinking valve or injury or death to an animal from the impact of the cage falling from the rack. One such system is disclosed in U.S. Pat. No. 5,954,015, the contents of which is incorporated herein be reference.
While related cage locks work for their intended purposes, a deficiency of related cage locks is that the lock has to be grasped in order to switch it between the locked and unlocked positions when inserting a cage. Another deficiency of related locks is that changing the position of the lock to accommodate a different cage size is cumbersome because it requires an operator to pull a retaining member away from a base member while at the same time rotating the retaining member 180 degrees. These cage locks typically require a user to make use of the back of his or her hand to disengage the cage lock. Yet another deficiency with known locks is that it can be difficult to determine whether the locking mechanism is in the locked or unlocked position without carefully observing the state of the locking mechanism. Additionally, related cage locks are typically relatively large, thus obstructing a user's view to the cage interior. Related cage locks also typically contain a relatively large amount of components, such as springs, hinges and fasteners. This relative mechanical complexity leads to corresponding manufacturing and maintenance costs. Further more, related cage locks, due to the nature of their mechanical design, typically facilitate the marring of cage side walls. As such, a need exists for an improved cage locking mechanism and system.